CN105176694B

CN105176694B - A method of preparing biodiesel

Info

Publication number: CN105176694B
Application number: CN201410234984.XA
Authority: CN
Inventors: 王海京; 杜泽学; 高国强
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2014-05-30
Filing date: 2014-05-30
Publication date: 2019-01-08
Anticipated expiration: 2034-05-30
Also published as: CN105176694A

Abstract

The present invention provides a kind of method for preparing biodiesel, it include: using the chloride selected from II A, IV A race metal as catalyst, mix grease in the reactor with C1~C6 monohydric alcohol, at 100~300 DEG C of reaction temperature, it reacts under 0.1~5Mpa of pressure, the fractionation of fatty acid esters from the material after reaction.The method of the present invention handles oil plant under lower temperature and pressure condition, can get the biodiesel of high yield.

Description

A method of preparing biodiesel

Technical field

The present invention relates to the methods by grease and monohydric alcohol reaction preparation biodiesel.

Background technique

Biodiesel (i.e. fatty acid monoalkyl ester) can carry out ester exchange reaction by grease and monohydric alcohol and be made, and reaction produces There is fatty acid monoalkyl ester in object, there are also monoglyceride, two sweet esters, glycerol and unreacted pure and mild greases (i.e. triglycerides). In the prior art, the preparation method of biodiesel can be divided into acid catalyzed process, base catalysis method, enzyme catalysis method and supercritical methanol technology.

The leftover bits and pieces and edible oil recovery that CN1473907A uses vegetable oil refining for raw material, catalyst by sulfuric acid, hydrochloric acid, P-methyl benzenesulfonic acid, dodecyl benzene sulfonic acid, naphthalene sulfonic acids etc. are inorganic and organic acid compounds, acidified removal of impurities, continuous dehydration, ester The processes such as change, layering, vacuum distillation are produced, and the pressure of continuous vacuum dehydration is 0.08~0.09Mpa, temperature 60~95 DEG C, dehydration is to water content 0.2% hereinafter, esterif iotacation step catalyst charge 1~3%, and 60~80 DEG C of esterification temperature, the reaction time 6 hours.Product, which first neutralizes, after reaction removes catalyst, and then, layering removes water, and product is gone after water to obtain biology through vacuum distillation Diesel oil.Acid catalyzed problem is that reaction speed is slow, has a large amount of spent acid and generates, pollutes environment.

JP9-235573, which is disclosed, a kind of prepares diesel engine in the presence of sodium hydroxide with discarded edible oil and methanol Fuel, but in natural oil, free fatty acid is usually contained, in the case where free fatty acid is more, is catalyzed using alkali metal Agent, can generate fatty acid soaps, and such base metal catalysts want excess and separate fatty acid ester layer with glycerin layer to become difficult.

DE3444893 discloses a kind of method, with acid catalyst, normal pressure, 50~120 DEG C, by free fatty acid and alcohol into Row esterification carries out pre-esterification processing, the acid catalysis that ester exchange reaction is then carried out under base metal catalysts, but is left to oil plant Agent will be will increase by alkali neutralization, the amount of base metal catalysts.Using pre-esterification, keep processing flow elongated, equipment investment, energy consumption is high Width rises, in addition, basic catalyst need to be removed from product, has a large amount of waste water to generate, and recycling glycerol is difficult.

US5713965A discloses a kind of method, and in the presence of lipase, hexane makees solvent, grease and alcohol reaction preparation Fatty acid methyl ester, i.e. diesel fuel.

CN1472280A discloses a kind of method, using aliphatic ester as acyl acceptor, in the presence of biological enzyme, and biology It is catalyzed transesterification reaction and produces biodiesel.Be using deficiency existing for enzyme catalyst: the reaction time is long, efficiency is lower, and enzyme is more expensive, And the easy in inactivation in high purity methanol.

A kind of method that CN1111591C discloses grease and monohydric alcohol reaction prepares aliphatic ester, this method includes by first Alcohol obtains aliphatic ester with grease reaction, and at 270~280 DEG C, under the conditions of 11~12Mpa, fatty acid methyl ester production rate is 55 ~60%, fatty acid methyl ester production rate is lower.

Summary of the invention

The present invention provides a kind of method for preparing biodiesel, and this method handles oil under lower temperature and pressure condition Material can get the biodiesel of high yield.

The method of preparation biodiesel provided by the invention include: using metal chloride as catalyst, make grease and C1~ C6 monohydric alcohol mixes in the reactor, reacts under 100~300 DEG C of reaction temperature, 0.1~5Mpa of pressure, after reaction Material in fractionation of fatty acid esters.

The main component of the grease is fatty acid triglycercide, including various animal and plant fats, additionally includes and Oil plant from the substances such as microorganism, algae.Vegetable fat for example soybean oil, rapeseed oil, peanut oil, sunflower seed oil, palm oil, Coconut oil and the object containing fat-based from the fruit of various other crops and wild plant, stem, leaf, limb and root Matter (including the tall oil generated in paper-making process).Animal fat such as lard, butter, sheep oil, fish oil etc..The grease can be with It is non-polished fat, polished fat, acidification grease and waste grease etc..

The monohydric alcohol refers to unitary fatty alcohol of the carbon atom number between 1~6, can be saturated alcohols or unsaturation Alcohol.Such as methanol, ethyl alcohol, propyl alcohol, isopropanol, allyl alcohol, n-butanol and its isomers, amylalcohol and its isomers.It can be used single Only alcohol or their mixture.It is preferred that methanol and/or ethyl alcohol.

The catalyst is the chloride selected from II A, IV A race metal, and preferably the catalyst is stannous, tin, barium Chloride, the additional amount of catalyst are 0.01~5%, preferably 0.1~3%, more preferable the 0.5~2% of grease weight.

The reactor is tank reactor, preferably autoclave.Grease, pure and mild catalyst are added in reactor, filled It is reacted after dividing mixing, obtains reacting coarse product, be filtered to remove solid catalyst, steam unitary from liquid phase reactor crude product Alcohol separates mixed ester phase (containing aliphatic ester, monoglyceride, two sweet esters, unreacted triglycerides) with glycerol, by mixed ester Mutually passes through distillation respectively with glycerol and obtain high purity fatty acid ester and glycerol.

Temperature of reactor be 100~300 DEG C, preferably 110~220 DEG C, more preferable 120~160 DEG C, 0.1~5Mpa of pressure, It is preferred that the weight ratio of 0.2~2Mpa, more preferable 0.4~1Mpa, grease and monohydric alcohol is 1:0.05~2, preferred 1:0.1~1, more Preferably 1:0.1~0.4.The haptoreaction time 0.1~10 hour, preferably 0.5~5 hour, more preferable 1~4 hour.

Temperature increases, and reaction conversion ratio is higher, because temperature raising is conducive to reaction and carries out for aerodynamic point, But when temperature is higher than 300 DEG C, reaction product is black, has burnt matter to generate, meanwhile, also result in glycerol decomposition, therefore, reaction Device temperature answers 300 DEG C of <, preferably 100~300 DEG C.

Pressure is higher more advantageous to reaction, but pressure is too high, improves the investment of device and operating cost more, so, 0.1~5Mpa of pressure, preferably 0.2~2Mpa, more preferable 0.4~1Mpa.

The molar ratio of monohydric alcohol and grease can change in very large range in the method for the present invention, the molar ratio mistake of methanol and oil Height can make material shorter residence time in the reactor, conversion ratio decline.Also increase plant energy consumption and operating cost, make equipment Utilization rate decline.So the mass ratio of monohydric alcohol and grease can be 1:0.05~2, preferably 1:0.1~1, more preferably 1:0.1~0.4.

The applicable feedstock oil of the method for the present invention is very extensive, and acid value can change within a large range, be particularly suitable for height Acid value, high impurity oil plant, such as 0~200mgKOH/g of acid value, preferably 60~150mgKOH/g, unsaponifiable matter content is up to 4~ The grease of 10g/100g.

The metal chloride catalyst that the present invention uses has the characteristics that high activity, low cost, is applicable in the reaction of low pressure, low temperature The biodiesel of high yield can be obtained by single step reaction for condition.

Specific embodiment

The present invention is further illustrated below by example, but the present invention is not limited thereto.

Embodiment 1

By the acidification oil 100g of acid value 117mgKOH/g, protochloride of the alcohol oil quality than 0.20, with grease weight 0.6wt% Tin is added in autoclave together, under conditions of 140 DEG C of autoclave temp, pressure 0.7Mpa, 200 revs/min of mixing speed, instead It answers 3.5 hours, obtains reacting coarse product and distilled, 150 DEG C of removing methanol of < in bottom, and methanol is recycled, is repeated It uses, after surplus material is isolated glycerol phase, obtained mixed ester is mutually evaporated under reduced pressure, the high-purity rouge that tower top obtains Fatty acid methyl esters are biodiesel, and the yield of biodiesel is 92%, acid value 6.0mgKOH/g.

Embodiment 2

By the soybean oil 100g of acid value 0.7mgKOH/g, chlorination of the alcohol oil quality than 0.20, with grease weight 0.77wt% Tin is added in autoclave together, under conditions of 140 DEG C of autoclave temp, pressure 0.7Mpa, 200 revs/min of mixing speed, instead It answers 3.5 hours, obtains reacting coarse product and distilled, 150 DEG C of removing methanol of < in bottom, and methanol is recycled, is repeated It uses, after surplus material is isolated glycerol phase, obtained mixed ester is mutually evaporated under reduced pressure, the high-purity rouge that tower top obtains Fatty acid methyl esters are biodiesel, and the yield of biodiesel is 90.7%, acid value 2.4mgKOH/g.

Embodiment 3

By the soybean oil 100g of acid value 1.7mgKOH/g, protochloride of the alcohol oil quality than 0.17, with grease weight 0.6wt% Tin is added in autoclave together, under conditions of 130 DEG C of autoclave temp, pressure 0.4Mpa, 200 revs/min of mixing speed, Reaction 3.5 hours, obtains reacting coarse product and is distilled, 150 DEG C of removing methanol of < in bottom, and is recycled to methanol, again It is multiple to use, after surplus material is isolated glycerol phase, obtained mixed ester is mutually evaporated under reduced pressure, the high-purity that tower top obtains Fatty acid methyl ester is biodiesel, and the yield of biodiesel is 85.5%, acid value 0.4mgKOH/g.

Embodiment 4

By the soybean oil 100g of acid value 0.6mgKOH/g, chlorination of the alcohol oil quality than 0.17, with grease weight 0.77wt% Tin is added in autoclave together, under conditions of 130 DEG C of autoclave temp, pressure 0.4Mpa, 200 revs/min of mixing speed, instead It answers 4 hours, obtains reacting coarse product and distilled, 150 DEG C of removing methanol of < in bottom, and methanol is recycled, repeats to make With after surplus material is isolated glycerol phase, being mutually evaporated under reduced pressure to obtained mixed ester, high-purity that tower top obtains fat Sour methyl esters is biodiesel, and the yield of biodiesel is 85%, acid value 1.6mgKOH/g.

Embodiment 5

By the acidification oil 100g of acid value 120mgKOH/g, barium chloride of the alcohol oil quality than 0.20, with grease weight 1.5wt% It is added in autoclave together, under conditions of 150 DEG C of autoclave temp, pressure 0.9Mpa, 400 revs/min of mixing speed, reaction It 3.5 hours, obtains reacting coarse product and is distilled, 150 DEG C of removing methanol of < in bottom, and methanol is recycled, repeats to make With after surplus material is isolated glycerol phase, being mutually evaporated under reduced pressure to obtained mixed ester, high-purity that tower top obtains fat Sour methyl esters is biodiesel, and the yield of biodiesel is 80%.

Embodiment 6

By the acidification oil 100g of acid value 120mgKOH/g, chlorination of the alcohol oil quality than 0.17, with grease weight 0.77wt% Barium is added in autoclave together, under conditions of 160 DEG C of autoclave temp, pressure 1.1Mpa, 200 revs/min of mixing speed, instead It answers 3.5 hours, obtains reacting coarse product and distilled, 150 DEG C of removing methanol of < in bottom, and methanol is recycled, is repeated It uses, after surplus material is isolated glycerol phase, obtained mixed ester is mutually evaporated under reduced pressure, the high-purity rouge that tower top obtains Fatty acid methyl esters are biodiesel, and the yield of biodiesel is 88.1%, acid value 23.1mgKOH/g.

Comparative example 1

Biodiesel is prepared according to the method for embodiment 3, unlike, stannous chloride is substituted with zirconium oxychloride, biological bavin The yield of oil is 30.7%.

By embodiment 3 compared with comparative example 1, illustrate that the chloride catalytic activity difference of different metal is very big.

Claims

1. a kind of method for preparing biodiesel, comprising: mix grease in the reactor with C1~C6 monohydric alcohol and catalyst, It reacts under 100~300 DEG C of reaction temperature, 0.1~5MPa of pressure, the fractionation of fatty acid esters from the material after reaction, institute Stating catalyst is stannous chloride, and the additional amount of the catalyst is the 0.01~5% of grease weight.

2. according to the method for claim 1, wherein the monohydric alcohol is methanol and/or ethyl alcohol.

3. according to the method for claim 1, wherein the additional amount of the catalyst is the 0.1~3% of grease weight.

4. according to the method for claim 1, wherein the reactor is autoclave.

5. according to the method for claim 1, wherein temperature of reactor is 110~220 DEG C, 0.2~2MPa of pressure.

6. according to the method for claim 1, wherein temperature of reactor is 120~160 DEG C, 0.4~1MPa of pressure.

7. according to the method for claim 1, wherein the weight ratio of grease and monohydric alcohol is 1:0.05~2, when haptoreaction Between 0.1~10 hour.

8. according to the method for claim 1, wherein the acid value of oil and fat is 0~200mgKOH/g, and unsaponifiable matter content is 4~10g/100g.